1. Technical Field
The present disclosure relates to air conditioning systems and, in particular, to efficient-enhanced reversible air conditioning systems capable of both heating and refrigeration.
2. Description of the Related Art
Heating and cooling systems may include a compressor for compressing a working refrigerant fluid, a condenser heat exchanger for extracting heat from the refrigerant fluid, an expansion valve, and an evaporator heat exchanger for extracting heat from an external source. In some instances, such refrigeration systems may further include an economizer heat exchanger and/or a vapor injection feature associated with the compressor for increasing both the capacity and the efficiency of the compressor.
In typical refrigeration systems, the refrigerant is a high pressure hot liquid upon leaving the compressor, is a high pressure warm liquid downstream of the condenser, is a low pressure warm gas downstream of the expansion valve, and is a low pressure cool gas downstream of the evaporator.
An economizer may be used to further influence the thermal state of the refrigerant between the condenser and evaporator. An auxiliary refrigerant flow is tapped from the main refrigerant flow downstream of the economizer heat exchanger and passed through an expansion valve to expand the auxiliary refrigerant flow before same is passed back through the economizer heat exchanger in heat exchange relation with the main refrigerant flow. This serves to further subcool the main refrigerant flow upstream of the evaporator.
The economizer heat exchanger also discharges an auxiliary refrigerant flow in the form of an intermediate pressure vapor, which is then injected into the compressor. Typically a scroll compressor is used in connection with such a system, and the vapor is injected at an intermediate pressure location within the wraps of the scroll compressor.
Further increases in efficiency and capacity are desirable in air conditioning systems, in order to increase system efficacy and/or decrease the cost of operating the system.